Flexible seal



P'. E. VERAAI' FLEXIBLE SEAL" F-il-ed Ma'rGh 27, 1952 Jan. 10,. 1956 IN V EN TOR. Pfif/ 0/: Z. Vercza ATTORNEY United States Patent FLEXIBLE SEAL Philemon E. Veraa, Hohokus, N. J., assignor to interchemical Corporation, New York, N. Y., a corporation of Ohio Application March 27, 1952, Serial No. 278,736

2 Claims. (Cl. 219-418) This invention refers to an improvement in electrically heated kettles and more specifically to a flexible seal between the kettle and the surrounding high temperature furnace.

The heated kettle is an integral and essential unit in the paint, varnish, oil, chemical and other industries. The rapidity, control and even distribution of the heat ap plied to the kettle are vital factors in the quality of the product in most instances. Continuous efforts have been made in the past to improve these factors and the trend has been from wood, coal or coke fires, with natural or forced draft, to oil and gas and, finally, to electrically heated kettles. By mounting the heating elements around the intercircumference of an insulating jacket, heating is accomplished by radiation rather than by contact. This eliminates localized over-heating and consequent damage to kettle walls and scorching or burning of the kettle contents.

The design of an electrical kettle or reactor furnace offers no difliculties as long as the heating elements are restricted in position adjacent to the side of the kettle; the required confined heating zone can be readily produced by enclosing the insulating jacket on top and bottom against the kettle wall. However, the heat transfer within the material contained in the kettle is slow in many instances and it is desirable to provide additional heating elements adjacent to the bottom of the kettle. Because the kettles are commonly equipped with an outlet or drain in the center of the bottom, the accepted practice has been to Weld a cylindrical sleeve to the bottom of the tank with the drain pipe centered therein, and to place the lower part of the said sleeve in a sand seal, provided within a container of annular shape with concentric side walls, the outside wall being joined to the bottom part of the insulating casing.

This sand seal has been proved unsatisfactory in many cases The kettle expands when heated and since it is, as a rule, fixedly attached at its upper portion to the refractory wall, the direction of expansion upon heating is downward. Consequently, the height to which the cylindrical Often the sand besleeve is embedded in the sand varies. comes tightly packed and the sleeve cannot penetrate it upon heat-expansion of the kettle which results in immense stresses at the joints and frequent maintenance work. Moreover, the sand does not provide a vapor-proof seal and since it is diflicult, as a rule, to keep the outlet absolutely leak-proof, the danger of explosion always exists when a kettle having the foregoing arrangement contains solvents which, because of an undiscovered or sudden leak, penetrate into the enclosed heating zone.

The present disclosure refers to a flexible seal between a kettle and a surrounding high temperature electric furnace which is constructed to allow for differences in the expansion coeflicient between the kettle and the insulating or refractory jacket. The principal advantage of the dis- 2,730,606 Patented Jan. 10, 1956 "Ice closure rests in the fact that vapor penetration into the enclosed heating zone is impossible.

The invention is illustrated by the accompanying drawing which represents a cross-sectional view of an electrically heated kettle having the herein claimed flexible seal.

In the drawing, a kettle 10 is shown, having an annular support 11 welded thereto near the top. The annular support is provided with properly spaced bracket leaves 12 with vertical beams 14 centered underneath on which the kettle is mounted. The kettle is equipped with a bottom drain 15, operated by the drain valve 16. Most kettles of this type are equipped with a rake or other mixing device, such as the agitator 17.

The kettle is set within an insulating casing 20, preferably constructed from a suitable refractory material, having electric heating elements, such as the elements 21, mounted thereon adjacent to the side and the bottom of the kettle. As shown in the drawing, the insulating casing is provided with a steel housing 22 and is also bolted to the afore-mentioned annular support 11, to provide suflicient space underneath for mounting and operating the drain and drain valve.

A circular opening is provided in the bottom part of the insulating casing to accommodate the drain. Such an opening having a diameter of about 12 inches is about adequate for a 3 inch drain pipe. The flexible seal which encloses the drain and completely separates it from the heating zone between the kettle and the interior of the insulating casing consists of two main parts, a stainless steel tapered sleeve 30 which is continuously welded to the bottom of the tank and has a flanged and drilled ring at the lower end for juncture with the other part which is a diaphragm ring 31, made flexible by providing one or more circular corrugations such as shown at 32. The diaphragm ring is attached to the bottom of the steel housing 22 of the insulating casing and is jointed to the tapered sleeve 30 by means of bolts such as shown at 34, with an asbestos gasket 35 therebetween.

Having described my invention, I claim:

1. In conjunction with a kettle having a bottom outlet and an insulating jacket with electric heating elements mounted thereon adjacent to the wall and bottom of the kettle, the said insulating jacket serving to support the said kettle in a hanging position and being dimensioned to provide a heating Zone between the kettle and the inner sur face of the jacket and an opening around the said outlet, the improvement of a flexible seal between the kettle and the surrounding insulating jacket which accommodates the said outlet and comprises a sleeve from heat resisting material which at the upper end is continuously fastened to the bottom of the kettle and at the lower end expands into a ring which has at least one concentric corrugation and at the periphery is fixedly attached to the bottom part of the insulating jacket.

2. The improvement according to claim 1, wherein a stainless steel tapered sleeve which at the upper end is continuously welded to the bottom of the kettle has a flange at the lower end and, by means of bolts passing through the said flange and an asbestos gasket thereunderneath is jointed to a stainless steel ring which has at least one concentric corrugation and at the periphery is fixedly attached to the bottom part of the insulating jacket.

References Cited in the file of this patent UNITED STATES PATENTS 1,115,678 Kaiser Nov. 3, 1914 1,270,406 Goecke June 25, 1918 1,690,820 Hornsey Nov. 6, 1928 2,521,102 Vedovell Sept. 5, 1950 

